f Geometric Seismic Attributes for Imaging High Angle Faults and Thin Beds in the Magangue High, Northwestern Colombia

New natural gas discoveries in the Magangue High (Northwestern Colombia) brings new exploration opportunities but also new challenging conditions in an underexplored area. The principal reservoir is related to the Lower Miocene transgressive sandstones (Cienaga de Oro Formation), characterized by a high-energy well-connected marginal marine channel system that ended isolated thin tidal channels. The secondary reservoir is related to early Late Miocene Basal Porquero Formation turbidite sandstones. These two intervals are limited by normal faults, which both generate trap and compartmentalize the reservoir. The first objective of this work was to better map high-angle faults. Seismic attributes such as eigenstructure coherence are sensitive only to waveform changes while others such as Sobel filters and variance are sensitive to both waveform and amplitude changes. In contrast, attributes such as the most-positive and most-negative principal curvatures are sensitive to more diffuse fault zones that appear as flexures. The second objective was to apply geometric seismic attributes sensitive to amplitude changes to image channel features with thickness possibly below tuning resolution. Applying this workflow are able to image thin tidal channels and sand flats that give rise to amplitude changes. We interpret the amplitude contrast between channel infill and surrounding matrix as representing more sandy intervals. We interpret other channels as filled with clay plugs, with reservoir characterization consequences. Co-rendering coherence attributes combined with the principal curvatures were effective in mapping normal faults in the Magangue Arc, key to reservoir characterization and well planning phases.